Saturday, April 5, 2014

Old Telescope

Nighttime Observing


In 1975 I bought my first telescope, a Celestron 8-inch Schmidt-Cassegrain. Over the years I've used it many times and learned lots about observing and telescope operation. Recently, however, I haven't used it much because its old fork mount is so hard to use compared to newer computer controlled mounts.

A few weeks ago I purchased adapters to attach the aged Celestron to my beautiful Paramount MX mount. On April 2nd, after a full afternoon of solar imaging with a hydrogen-alpha solar telescope, I used the Celestron to image sunspots through a mylar filter. These sunspot images were poor, but the sky was clear and the weather mild. So I decided to leave the equipment outside and wait for darkness.

The evening session began with a quick look at some familiar celestial sights through an ordinary eyepiece. Then I decided to image Jupiter and the Moon. I attached my DMK41 video camera at the Celestron's prime focus and focused with difficulty on Jupiter. Over the years the Celestron focus has been soft, and this night was no exception. The Jupiter image below was produced by capturing 2,000 video frames, aligning them in Registax 6, stacking the best 100 frames, and then sharpening the final image using wavelets in Registax 6. I have no color filters, so the image is monochrome.

Although seeing was mediocre, some details on Jupiter are barely visible. For example, there are hints of circular features just below the equator. Three moons are visible. From left to right they are: Europa, Io, and Ganymede. The fourth moon, Callisto, was out of view off to the right. Some details reach the threshold of visibility, but are nowhere near the resolution achieved by experts in planetary imaging.
I also captured 7 pictures of the crescent Moon and combined them in the following 7-image mosaic. A slight pale blue color has been added. (Click on the image for a larger view.)
Sunspot images with the Celestron were very disappointing, but hydrogen-alpha solar pictures from the afternoon of April 2nd were much better. I'll post them in my next blog.

1 comment:

  1. I love that moon picture. That is exactly how I remember the moon looking the last time I got to look through your telescope, ages ago. I hope Sophie will enjoy it too when she's a bit older.

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People say I'm crazy doing what I'm doing
Well they give me all kinds of warnings to save me from ruin
When I say that I'm o.k. well they look at me kind of strange
Surely you're not happy now you no longer play the game

People say I'm lazy dreaming my life away
Well they give me all kinds of advice designed to enlighten me
When I tell them that I'm doing fine watching shadows on the wall
Don't you miss the big time boy you're no longer on the ball

I'm just sitting here watching the wheels go round and round
I really love to watch them roll
No longer riding on the merry-go-round
I just had to let it go

John Lennon